title: Principles and applications of polymerase chain reaction: basic science for the practicing physician.
abstract: OBJECTIVE
  To review the technology of polymerase chain reaction (PCR) and its use in diagnostic medicine and biomedical research.
  
  
  METHODS
  A literature review was performed using the PubMed database for English-language articles published between January 1, 1985, and November 31, 2007, using the following keywords: polymerase chain reaction, real-time polymerase chain reaction, and applications of real-time polymerase chain reaction.
  
  
  METHODS
  Select review articles and primary articles relevant to medical applications of PCR were chosen.
  
  
  RESULTS
  As a revolutionary technique, PCR provides a rapid and accurate means of amplifying DNA. It has enabled the cloning and manipulation of genes for biomedical research and has facilitated the diagnosis of genetic, infectious, and oncologic diseases. The use of reverse transcriptases to evaluate RNA levels and the extension of PCR technology to quantify DNA amplification in real time has brought major advances to the application of PCR. By allowing the determination and quantification of changes in gene expression, these techniques have provided a greater understanding of disease processes and now serve as a foundation for diagnostics and basic science research.
  
  
  CONCLUSIONS
  Both PCR and real-time PCR have dramatically changed the field of basic science and diagnostic medicine. These technologies are now a well-established, indispensable part of research and clinical laboratories.
authors.affiliation: Division of Allergy and Clinical Immunology, Johns Hopkins University, Baltimore, Maryland 21224, USA.
authors.forename: Faoud T
authors.initials: FT
authors.lastname: Ishmael
authors.forename: Cristiana
authors.initials: C
authors.lastname: Stellato
mesh_terms: D019937:Diagnostic Techniques and Procedures; D020869:Gene Expression Profiling / Q000379:methods; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity